The objectives of this study are to document and describe alterations in the appearance of the retinal nerve fiber layer that accompany glaucomatous visual field loss; and to determine the reliability and value of such changes, alone and in combination with the appearance of a variety of disc parameters, as a means of identifying individuals already having visual field loss, and predicting which ocular hypertensives will eventually develop field loss. Normal controls, ocular hypertensives, and patients with established glaucomatous field loss will be followed prospectively, repeatedly examined, and their disc and nerve fiber layer photographed. These photographs will be read in masked, randomized, controlled fashion and the sensitivity and specificity of the test, in temporal relationship to the eventual onset of glaucomatous field loss, determined.